The overall goals of the Program are to answer two fundamental questions: 1) How do bacterial species colonize the catheterized urinary tract? 2) How do these bacteria damage or cross the epithelium? The function of the Core is to provide resources and expertise to the Project Directors in the investigations which have been designed to answer these questions. The long-term objectives of the Core are three-fold: 1) to maintain excellent support laboratories which will be used by investigators in the Projects, 2) to supply expertise in data analysis and statistical testing, and 3) to provide administrative assistance to coordinate the Program. The core has three support laboratories, each of which provides a critical research element: 1) Cell Culture Section: Human renal epithelial cell cultures including proximal tubular, collecting duct, and pelvic epithelial cells among which are the target cells for organisms causing acute pyelonephritis. 2) Animal Model Section: A well-characterized murine model of acute pyelonephritis which we have additionally modified to examine the role of a long-term intra-bladder urinary catheter. 3) Microbiology/Pathology Section: A library of catheter-associated bacteriuric and pyelonephritogenic bacteria as well as fecal control strains from healthy volunteers. The Core Directors of the support laboratories furthermore provide expertise in experimental pathology, electron microscopy, immunofluorescence and immunogold techniques, DNA probes, hemagglutination and inhibition, monoclonal antibody development, and numerous pertinent subcellular biochemical reactions. Additionally, the Biostatistics Section provides expert statistical analysis for all aspects of the investigations. The Administration Section provides overall administrative support to insure effective use of resources and talent.